摘要
用Ｘ射线衍射、电子显微镜、Ｘ射线光电子能谱和振动样品磁强计对在１０和１８ｋＰａ压强的氩气中以铁和碳作为电极，通过交流电弧法制备的微粒进行了分析。结果表明，用此方法可制取纳米量级的合金微粒。所形成的微粒有两类：一类是六方ＦｅＣ微粒，另一类为立方铁微粒。铁微粒具有心部为α-Ｆｅ、外部为Ｆｅ３Ｏ４、ＦｅＯ及非晶的ＦｅＯ（ＯＨ）的多层结构。在不同压强下，Ｃ进入铁微粒的程度不同，从而使铁微粒的抗氧化能力不一样，因此α-Ｆｅ的含量不同。此外，由于碳对铁的晶化性质的影响，可使铁微粒的粒径随之改变。在两种不同压强下制得的Ｆｅ—Ｃ微粒由于α-Ｆｅ含量和粒径的不同，其比饱和磁化强度 ｓ和矫顽力Ｈｃ也有差异。由于Ｆｅ—Ｃ微粒中的铁微粒的结构随温度的变化，磁化强度ｓ从２００—２８０℃出现异常增加。
?The particles prepared by alternate are discharging between Fe and C electrodes in10 or 18kPa of Ar gaseous have been analysted by XRD, TEM, XPS and VSM. The resultsshow that nano-partides can be produced by the method and there were two typic formedpartides, ortho -hexagonal Fe-C and cubic iron. The iron particles has multiplayer structure,Whose core is a-Fe wrapped up in Fe3O4 and non crystal FeO(OH) outsidle layers. Theanti--oxidaton effect as well as the a-Fe content of the particles prepared in different pressureof Ar gaseous, due to the difference of carbon content in them, are not same. As the crystalproperty of iron is influence by carbon, the size of iron partides would change with its' carbon content. For the Fe-C partides obtained in the two dtherent Ar gaseous, the difference ofa-Fe contacts and sizes led to their staturation magentization and coercivity Hc different.And also, the structure of iron particles in Fe-C particles would change with temperature, sothat Fe-C particles' magnetization s unusually increased with temperature increased from200℃ to 280 ℃.
